As today's workplace becomes increasingly sophisticated and technologically complex, workers are experiencing ever increasing demands on their competence, awareness, and abilities. Workers increasingly rely on technologically complex equipment to support proper workplace functioning. Moreover, the workers, as operators of this equipment, must function efficiently and safely at every moment. In particular, the level of mental alertness of the operator is of vital importance: Is he engaged? Is he overloaded? Is he bored? Is he distracted? Is he fatigued? Knowing the mental alertness level of the operator at any moment would allow the operator's supervisor or the equipment itself to know if the operator is at a level that may decrease productivity or pose a safety risk. Either the technology itself or the operator's supervisor could then raise an alarm and take appropriate action such as relieving the operator or providing additional support.